China first rotomolding factory use PP material to make big rotational molding products

For rotomolding products , it is very difficult to use PP material to make products.

First of all, let’s see the particularity of the material.

PP material density is small, strength stiffness, hardness and heat resistance are better than low pressure polyethylene, can be used at about 100 degrees, has good electrical performance and high frequency insulation is not affected by humidity. Such characteristics of plastic should originally be the main force of domestic rotomolding products, but as a manufacturer, we have to consider the molding characteristics of PP material.
1.Crystallized material, small hygroscopic, easy to melt rupture, long-term contact with hot metal easy to decompose.
2.The fluidity is good, but the shrinkage range and shrinkage value are large, and shrinkage holes are easy to occur.
3. The cooling speed is fast, the pouring system and cooling system should dissipate heat slowly, and pay attention to control the molding temperature. When the material temperature is low temperature and high pressure, it is easy to Orient. When the mold temperature is below 50 degrees, the plastic parts are not smooth, easy to produce poor fusion, flow marks, and easy to warp and deformation above 90 degrees 4. Plastic wall thickness must be uniform, avoid lack of glue, sharp corners, to prevent stress concentration.

In conclusion, the performance of PP material is not stable, and the molding time of rotomolding products is long, so it is not suitable to use PP material as raw material.

When our customer give this question, we said no without any consideration. The limitation of traditional thinking prevents us from trying new materials. It can be thought that if PP material is really used to make this product, we are a rare rotomolding manufacturer in China, Because it is very rare to use PP material to make rotomolding products. So we decided to give it a try,and it is worth to do it. The process was easier than we imagined. After an hour, a rotomolding product made of PP material appeared in front of us. The new product is much tougher than the usual roto-molded product. The surface also has more gloss. Compared with ordinary pp materials, this product is more ductile and not easy to damage.

With the advantages of both PP and PE, we developed our strengths and avoided our weaknesses. We used our own expertise to complete this highly difficult job in the industry. In the future, we don’t have to worry about customers’ demand to make products with PP material. With the advantages of both, our products will definitely become more and more outstanding.